Novel chain transfer agent and emulsion polymerization using the same

ABSTRACT

To provide a novel compound having both a surface-activating ability and a polymerization controlling ability. 
     A compound represented by the following general formula (1) or (2): 
     
       
         
         
             
             
         
       
         
         
           
             wherein, R 1  and R 3  are an organic group having the hydrophile-lipophile balance (HLB) determined by Griffin&#39;s method of 3 or more. The definitions of R 1 , R 2 , R 3 , R 4 , Z, p and q are described in the Description.

FIELD OF THE INVENTION

The present invention relates to a RAFT agent having asurface-activating ability and a polymerization-controlling ability,more specifically emulsion polymerization using said RAFT agent, and apolymer obtained therefrom.

BACKGROUND OF THE INVENTION

Polymers having narrow molecular weight distribution havecharacteristics of having low viscosity compared to polymers havingbroad molecular weight distribution with the same number-averagemolecular weight. Block copolymers, compared to random copolymers,retain physical and chemical characteristics carried by each block, andfor example water soluble-nonwater soluble diblock copolymers, similarlyto low molecular weight emulsifying agents, have characteristics offorming micelles in an aqueous solution with the water soluble blockfacing the aqueous phase and the nonwater soluble block as the core. Inorder to obtain polymers and block copolymers having narrow molecularweight distribution, a sophisticated function of controllingpolymerization is required.

As a polymerization method having a sophisticated function ofcontrolling polymerization for obtaining a polymer and a block copolymerhaving narrow molecular weight distribution, living radicalpolymerization (sometimes referred to as “controlled radicalpolymerization”) is known. Depending on the mechanism of polymerization,several types of polymerization methods are known. Among them, apolymerization mechanism in which chain transfer during polymerizationproceeds reversibly is useful as a polymerization method to obtain apolymer and a block copolymer having narrow molecular weightdistribution. As such a polymerization method, reversibleaddition-fragmentation chain transfer (hereinafter referred to as“RAFT”) polymerization has been proposed.

As a method of producing polymers, from the viewpoint of industrialproduction, emulsion polymerization is superior in terms of removingreaction heat and recovering polymers, and thus techniques of carryingout controlled radical polymerization using emulsion polymerization maybe desired. Various investigations have been made on emulsionpolymerization that employs “RAFT agent,” a polymerization controllingagent that permits RAFT polymerization. In emulsion polymerization,however, an emulsifying agent in addition to a RAFT agent must generallybe added, which in many cases may markedly reduce polymerization speedor reduce latex stability. Thus, in emulsion polymerization thatrequires the addition of an emulsifying agent in addition to the RAFTagent, it is known that its ability of controlling molecular weight ispoorer than the homogeneous solution polymerization, and thus there is aneed for a RAFT agent that acts not only as an emulsifying agent butalso as a polymerization controlling agent.

Patent Document 1 illustrates a compound that serves as both anemulsifying agent and a polymerization initiator. However, the molecularweight distribution shown in the Examples of Patent Document 1 has avery broad range, and thus it cannot be recognized to be superior tomolecular weight distribution in an emulsion polymerization that doesnot use controlled polymerization.

In Patent Document 2 and Non-patent documents 1 and 2, RAFT agentshaving introduced therein polyethylene glycol (PEG) units having asurface-activating ability are reported. However, in polymerizationusing this RAFT agent, PEG units may inevitably be introduced into theends of the polymer obtained, and though sulfur-containing units(derived from a RAFT agent; they are dithioester sites in many cases)that cause coloration can be removed during the post-treatment stepusing a radical-generating agent such as an azo compound and a peroxide,or an amine, it is difficult to remove PEG units as well that are siteshaving a surface-activating ability (hereinafter referred to as“surface-active sites”). As a result, polymers containing residual PEGunits may pose a problem of water absorptivity depending on the intendeduses.

PRIOR TECHNICAL DOCUMENTS Patent Documents

-   Patent Document 1: Kohyo (Japanese PCT Patent Publication) No.    2002-534499-   Patent Document 2: Kokai (Japanese Unexamined Patent Publication)    No. 2003-147312

Non-Patent Documents

-   Non-patent document 1: Macromolecules, 2008, Vol. 41, pp. 4065-4068-   Non-patent document 2: Macromolecules, 2009, Vol. 42, pp. 946-956

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The problem to be solved by the present invention is to provide a novelcompound that plays the role of both surface-activating ability andpolymerization controlling ability. Another problem is to provide apolymerization method that can control polymerization until it reaches ahigh conversion ratio. Another problem is to provide a polymerizationmethod that facilitates the synthesis of block copolymers. Furthermore,another problem is to provide a polymerization method that permits theremoval of surface active sites and sulfur-containing units that causecoloration during the post-treatment after polymerization.

Means to Solve the Problems

After intensive research, the present inventors have found that bydesigning an unprecedented RAFT agent in which a structure having asurface-activating ability has been introduced into a specific site ofthe RAFT agent, emulsion polymerization can be realized, andsulfur-containing units can be easily removed after polymerization.

Thus, by emulsifying a RAFT agent represented by the following generalformula and a vinyl monomer in an aqueous medium, followed by radicalpolymerization, polymerization control up to a high conversion ratio maybecome possible, and block copolymers can also be synthesized.Furthermore, by dissociating the chemical bond between the RAFT agentand the polymer after polymerization, the RAFT agent can be removed fromthe polymer.

Furthermore, from said polymer obtained by removing the RAFT agent bythe above method, surface active sites can also be removed by treatmentafter polymerization, and the polymer obtained can also be used as athermoplastic resin composition.

Effects of the Invention

Emulsion polymerization that uses a RAFT agent having asurface-activating ability of the present invention has an advantagethat not only can it enable polymerization control but RAFT agent unitshaving a surface-activating ability can be removed from the polymer.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1

A graph plotting the relationship between the polymerization time andthe polymerization conversion ratio obtained in Working Example 5,Comparative Example 1 and Comparative Example 3.

FIG. 2

A graph plotting the relationship between the polymerization conversionratio and Mn obtained in Working Example 5, Comparative Example 1 andComparative Example 3.

FIG. 3

A graph plotting the relationship between the polymerization conversionratio and Mw/Mn obtained in Working Example 5 and Comparative Example 1.

FIG. 4

A graph plotting the relationship between the polymerization time andthe polymerization conversion ratio obtained in Working Example 6,Comparative Example 2 and Comparative Example 4.

FIG. 5

A graph plotting the relationship between the polymerization conversionratio and Mn obtained in Working Example 6, Comparative Example 2 andComparative Example 4.

FIG. 6

A graph plotting the relationship between the polymerization conversionratio and Mw/Mn obtained in Working Example 6 and Comparative Example 2.

FIG. 7

A graph plotting the relationship between the polymerization time andthe polymerization conversion ratio obtained in Working Examples 7 to 9.

FIG. 8

A graph plotting the relationship between the polymerization conversionratio and Mn obtained in Working Examples 7 to 9.

FIG. 9

A graph plotting the relationship between the polymerization conversionratio and Mw/Mn obtained in Working Examples 7 to 9.

FIG. 10

A graph plotting the relationship between the polymerization time andthe polymerization conversion ratio obtained in Working Example 10 andComparative Example 5.

FIG. 11

A graph plotting the relationship between the polymerization conversionratio and Mn obtained in Working Example 10 and Comparative Example 5.

FIG. 12

A graph plotting the relationship between the polymerization conversionratio and Mw/Mn obtained in Working Example 10 and Comparative Example5.

MODE FOR CARRYING OUT THE INVENTION

When a compound represented by a thiocarbonylthio compound is added intothe radical polymerization system, it can act as a radicalpolymerization chain transfer agent. As such a compound, there can bementioned, for example, a compound having a thiocarbonylthio group (adithioester structure or a trithiocarbonate structure). The greater thechain transfer constant relative to vinyl monomers to be polymerized,RAFT polymerization may proceed while being controlled and the narrowerthe molecular weight distribution of the polymer becomes. Representativereaction mechanisms are shown below. The RAFT polymerization isdescribed in, for example, “HANDBOOK OF RADICAL POLYMERIZATION,” K.Matyjaszewski and T. P. Davis Ed., Wiley, 2002, on page 661 and after.As used herein, M in the reaction mechanism shown below represents avinyl monomer, and Pm and Pn represent m-mer and n-mer polymer,respectively.

k_(i), k_(t), k_(add), k_(-add), k_(β), k_(-β), k_(addp) and k_(-addp)represent the rate constant of respective reactions. R and Z aredifferent from the R and Z in the compounds represented by the generalformula (1) to (6) below, and are signs used to clearly explain thereaction mechanisms. A compound represented by a thiocarbonylthiocompound added to control polymerization by such a mechanism is called aRAFT agent.

The compound of the present invention is a compound having asurface-activating ability, and a compound that permits controlledradical polymerization by being added as a RAFT agent into thepolymerization system.

Thus, it is a compound represented by the following general formula (1)or (2):

wherein, R¹ and R³ each represent an organic group having ahydrophile-lipophile balance (HLB) determined by Griffin's method of 3or more,

Z represents a nitrogen atom, an oxygen atom, a sulfur atom, a methylenegroup, or an unsubstituted aromatic hydrocarbon group,

R¹ represents, when Z is other than a sulfur atom, a monovalent organicgroup having one or more carbons, and said monovalent organic group maycomprise at least one of a nitrogen atom, an oxygen atom, a sulfur atom,a halogen atom, a silicon atom and a phosphorous atom and may representa high molecular weight substance,

R¹ represents, when Z is a sulfur atom, a monovalent aliphatichydrocarbon group or aromatic hydrocarbon group having one or morecarbons that bind(s) to the sulfur atom at a primary carbon and saidmonovalent hydrocarbon group may comprise at least one of a nitrogenatom, an oxygen atom, a sulfur atom, a halogen atom, a silicon atom anda phosphorous atom, and may represent a high molecular weight substance;when a plurality of R¹ are present, they may be the same or different;and p is represented by an integer of 1 or more,

R² is a p-valent organic group having one or more carbons, and saidp-valent organic group may comprise at least one of a nitrogen atom, anoxygen atom, a sulfur atom, a halogen atom, a silicon atom, aphosphorous atom and a metal atom, and may represent a high molecularweight substance,

R³ represents, when Z is other than a sulfur atom, a q-valent organicgroup having one or more carbons, and the q-valent organic group maycomprise at least one of a nitrogen atom, an oxygen atom, a sulfur atom,a halogen atom, a silicon atom and a phosphorous atom, and may representa high molecular weight substance,

R³ represents, when Z is a sulfur atom, a monovalent aliphatichydrocarbon group or aromatic hydrocarbon group having one or morecarbons that bind(s) to the sulfur atom at a primary carbon; and q is aninteger of 2 or more, and

R⁴ represents a monovalent organic group having one or more carbons, andthe monovalent organic group may comprise at least one of a nitrogenatom, an oxygen atom, a sulfur atom, a halogen atom, a silicon atom, aphosphorous atom and a metal atom, and may represent a high molecularweight substance; and two or more of R⁴ may be the same or different.

Griffin's method will be briefly explained below.

Griffin's method defines HLB value=20×(sum of the molecular mass of thehydrophilic portion/molecular weight), and at the HLB value of about3-6, part of the molecule is dispersed in water and used as anemulsifier of water-in-oil (w/o) type emulsion. At the HLB value ofabout 6-8, the molecule, when well mixed, is dispersed in water tobecome milky and used as an emulsifier of w/o type emulsion and awetting agent. At the HLB value of about 8-10, the molecule is stablydispersed in water to become a milky juice and used as a wetting agentand an emulsifier of o/w type emulsion. At the HLB value of about 10-13,the molecule is semitransparently dissolved in water and used as anemulsifier of o/w type emulsion. At the HLB value of about 13-16, themolecule is transparently dissolved in water and used as an emulsifierof o/w type emulsion and a detergent. At the HLB value of about 16-19,the molecule is transparently dissolved in water and used as asolubilizer. While the above HLB value relates to a molecule as a whole,in the present invention the HLB value is defined for a functional groupas well in the following equation:

HLB value=20×(sum of the molecular mass of the hydrophilic portion in afunctional group/molecular mass of the functional group)

When the HLB value for a functional group determined by Griffin's methodis 3 or less, it means that the hydrophilicity is too low, and thus whensubjected to emulsion polymerization, its polymerization controllingability becomes poor thereby exhibiting a polymerization behaviorsimilar to known RAFT agents. The maximum of the HLB value is 20 as canbe seen from the defining equation.

Among the above compound (1) or (2), from the viewpoint of ease insynthesis and ease of polymerization control, Z may preferably be asulfur atom, or a substituted or unsubstituted aromatic hydrocarbon, andmore preferably an unsubstituted aromatic hydrocarbon. As R¹ and R³,among the organic groups having a HLB value of 3 or more determined byGriffin's method, polyethylene glycol, polypropylene glycol,polyethylene glycol/polypropylene glycol block copolymers andderivatives thereof may be preferred, and those containing a carboxylicacid metal salt or sulfonic acid metal salt may be more preferred.

Whereas R² and R⁴ are organic groups having one or more carbons thatbind to the sulfur atom, among the organic groups having one or morecarbons, those that can be eliminated by chain transfer may bepreferred, and among them, those that can bind to the sulfur atom at thesecondary carbon and those that can bind to the sulfur atom at thetertiary carbon may be preferred. Furthermore, those that can bind tothe sulfur atom at the tertiary carbon may be more preferred because oftheir excellent controlling ability during the initial phase ofpolymerization. Substituents that can bind to the secondary or tertiarycarbon may not be specifically limited as long as they do not inhibitpolymerization, a substituted or unsubstituted hydrocarbon group, asubstituted or an unsubstituted aromatic hydrocarbon, a cyano group andan ester group may be preferred. Among them, in terms of polymerizationcontrol, an unsubstituted hydrocarbon group, an unsubstituted aromatichydrocarbon group and a cyano group may be preferred. The number of saidsubstituents that bind to the secondary or tertiary carbon is two andthree for the secondary or tertiary carbon, respectively, in which thetype of said substituents may be different or the same. Specifically anorganic group represented by the following formula may be preferred, andboth of R²¹ and R²² may preferably be a methyl group.

wherein R²¹ and R²² are the same or different alkyl groups having 1-8carbons.

From the foregoing, among the compounds represented by compound (1) or(2), such compounds as are represented by (RAFT-1) to (RAFT-14) may bementioned as preferred examples. As used herein, M illustrated in(RAFT-2), (RAFT-4) to (RAFT-10) represents a metal, preferably an alkalimetal or an alkaline earth metal, and more preferably an alkali metal.

The above compound (1) or (2) may be synthesized by a known method. Forexample, in the synthesis of the above (RAFT-1), after protecting ahydroxy group of p-bromophenol, it is reacted with magnesium tosynthesize a Grignard reagent, and then reacted withbromoisobutylnitrile. After deprotection, it is dehydration-condensedwith a carboxylic acid-ended polyethylene glycol in which polyethyleneglycol and succinic anhydride were reacted and thus (RAFT-1) of interestcan be obtained. In the structure of (RAFT-1), Z corresponding tocompound (I) is a phenyl group representing an aromatic hydrocarbongroup.

In addition to the above, it can also be synthesized by a method inwhich after reacting p-bromophenol and polyethylene glycol, magnesium isreacted to synthesize a Grignard reagent, and then reacted withbromoisobutyronitrile to synthesize the compound.

In the structure of (RAFT-1), the molecular weight of polyethyleneglycol corresponding to R¹ can be adjusted depending on the desiredwater solubility. When water solubility is desired to be increased, itcan be adjusted by increasing the molecular weight of polyethyleneglycol. The HLB value of R¹ when n=1 is about 5.0.

In the synthesis of (RAFT-2), after protecting a hydroxy group ofp-bromophenol with chloroethanol, it is reacted with magnesium tosynthesize a Grignard reagent, and then reacted withbromoisobutylnitrile. After further deprotection, it is reacted withsuccinic anhydride, and then the carboxylic acid may be neutralized witha metal hydroxide such as sodium hydroxide or a metal carbonate such assodium carbonate, or a metal bicarbonate such as sodium bicarbonate tosynthesize the compound. In the structure of (RAFT-2), Z correspondingto compound (I) is a phenyl group representing an aromatic hydrocarbongroup, and when M is sodium, the HLB value of R¹ is about 11.7.

In the synthesis of (RAFT-3) or (RAFT-4) compounds, the reaction step ofsynthesizing a Grignard reagent may carried out in a manner similar tothe synthesis of (RAFT-1) or (RAFT-2), and in stead ofbromoisobutylnitrile it can be reacted with1,4-di(bromoisopropyl)benzene to synthesize the compound. In thestructure of (RAFT-3) or (RAFT-4), Z corresponding to compound (I) is aphenyl group representing an aromatic hydrocarbon group.

In the synthesis of (RAFT-6) or (RAFT-7) compounds, after protecting ahydroxy group of p-bromophenol, it is reacted with magnesium tosynthesize a Grignard reagent, and then reacted withbromoisobutylnitrile. After deprotection, it is reacted withtrimellitate anhydride, and then the carboxylic acid may be neutralizedwith a metal hydroxide such as sodium hydroxide or a metal carbonatesuch as sodium carbonate, or a metal bicarbonate such as sodiumbicarbonate to synthesize the compound. In the structure of (RAFT-6) or(RAFT-7), Z corresponding to compound (I) is a phenyl group representingan aromatic hydrocarbon group, and when M is sodium, the HLB value of R¹is about 11.1.

As a vinyl monomer for use in the present invention, there can bementioned, for example, (meth)acrylic acid; a (meth)acrylate ester suchas methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate,isopropyl (meth)acrylate, allyl (meth)acrylate, n-butyl (meth)acrylate,isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl(meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate,cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl(meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl(meth)acrylate, t-butylcyclohexyl (meth)acrylate, dodecyl(meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, phenyl(meth)acrylate, toluoyl (meth)acrylate, benzyl (meth)acrylate,2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate,3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate,2-hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl(meth)acrylate, γ-(methacryloyloxypropyl)tetramethylsilane, an ethyleneoxide adduct of (meth)acrylate, (meth)acrylate-terminated polyethyleneglycol on both ends, (meth)acrylate-terminated polypropylene glycol onboth ends, (meth)acrylate-terminated polybutylene glycol on both ends,trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl(meth)acrylate, 2-perfluoroethylethyl (meth)acrylate,2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, perfluoroethyl(meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl(meth)acrylate, perfluoromethyl-perfluoroethylmethyl (meth)acrylate,2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl(meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate;

an aromatic vinyl monomer such as styrene, vinyltoluene,α-methylstyrene, chlorstyrene, p-methoxystyrene, p-butoxystyrene,styrenesulfonic acid and a salt thereof;

a silicon-containing monomer such as vinyl trimethoxysilane and vinyltriethoxysilane;

maleic anhydride, maleic acid and a monoalkylester and a dialkylester ofmaleic acid;

fumaric acid and a monoalkylester and a dialkylester of fumaric acid;

a maleimide-based monomer such as maleimide, N-methylmaleimide,N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-hexylmaleimide,N-octylmaleimide, N-dodecylmaleimide, N-stearylmaleimide,N-phenylmaleimide and N-cyclohexylmaleimide;

a vinyl cyanide monomer such as acrylonitrile and methacrylonitrile;

an amide group-containing monomer such as acrylamide and methacrylamide;

a vinyl ester such as vinyl acetate, vinyl propionate, vinyl pivalate,vinyl benzoate and vinyl cinnamate;

an alkene such as ethylene and propylene;

a halogen-containing alkene such as perfluoroethylene,perfluoropropylene, vinylidene fluoride, vinyl chloride, vinylidenechloride, and allyl chloride;

a conjugated diene such as butadiene and isoprene; and

allyl alcohol.

They may be used alone or two or more of them may be used incombination.

Among them, in terms of physical properties of the product, an aromaticvinyl monomer, a (meth)acrylate ester and a vinyl cyanide monomer may bepreferred with a (meth)acrylate ester and a vinyl cyanide monomer beingmore preferred. As used herein the term “(meth)acrylate” refers to“methacrylate” or “acrylate.”

The polymerization of a vinyl monomer using the compound of the presentinvention permits polymerization control in radical polymerization, andenables the synthesis of a polymer and a block copolymer having narrowmolecular weight distribution.

As a polymerization method, there can be used mass polymerization,solution polymerization, suspension polymerization or emulsionpolymerization. Among them, because of the surface-activating ability tobe carried by the compound of the present invention, suspensionpolymerization or emulsion polymerization may be preferred, and becauseof the ease of removing heat during polymerization, emulsionpolymerization may be more preferred.

In emulsion polymerization, generally an emulsifying agent and adispersion stabilizer may be used. Since a RAFT agent having a HLB valueof 3 or more determined by Griffin's method for R¹ and R³ is used in thepolymerization method of the present invention, said RAFT agent can alsobe used as an emulsifying agent or a dispersion stabilizer, but inaddition to the RAFT agent of the present invention, there can also beused a known emulsifying agent such as an anionic emulsifying agent, anonionic emulsifying agent and a cationic emulsifying agent, ordispersion stabilizer. They may be used alone or two or more of them maybe used in combination.

As an emulsifying agent, there can be mentioned a sulfate-basedemulsifying agent such as sodium lauryl sulfate, a sulfonate-basedemulsifying agent such as sodium alkylbenzenesulfonate and sodiumalkyldiphenylethersulfonate, a sulfosuccinic acid-based emulsifyingagent, an amino group-containing emulsifying agent, and a fattyacid-based emulsifying agent containing a monofatty acid and succinicacid.

An initiator used in emulsion polymerization may be one generally usedin radical polymerization. As an initiator of radical polymerization,there can be mentioned, for example, an organic peroxide such as cumenehydroperoxide, t-butyl peroxide, benzoyl peroxide,t-butylperoxyisopropyl carbonate, di-t-butyl peroxide, t-butylperoxylaurate, lauroyl peroxide, succinic peroxide, cyclohexanoneperoxide and acetylacetone peroxide; a persulfate such as potassiumpersulfate and ammonium persulfate; an azo compound such as2,2′-azobisisobutylnitrile and 2,2′-azobis-2,4-dimethylvaleronitrile,and the like. Among them, an organic peroxide or a persulfate may bepreferred due to its high reactivity.

When an organic peroxide or a persulfate is used, a reducing agent maybe used. As a reducing agent, there can be mentioned mixtures such asferrous sulfate/glucose/sodium pyrophosphate, ferroussulfate/dextrose/sodium pyrophosphate, and ferrous sulfate/sodiumformaldehyde sulfoxylate/ethylenediamine acetate. The use of a reducingagent may be preferred since it can reduce polymerization temperature.

The amount used of a radical polymerization initiator may preferably be0.005-10 parts by weight relative to 100 parts by weight of a vinylmonomer, more preferably 0.01-5 parts by weight, and most preferably0.02-2 parts by weight. The lower limit of each of these ranges issignificant in terms of polymerization speed and production efficiency.Also, the upper limit is significant in terms of increased molecularweight, impact resistance and powder characteristics of a polymer.

The polymerization temperature in radical polymerization of the presentinvention may preferably be −50-200° C., and more preferably 0-150° C.In emulsion polymerization which is a polymerization method using wateras a medium, 40-120° C. may be preferred, and during polymerization at100° C. or higher, polymerization may be carried out under pressure.

Also, radical polymerization using a compound of the present inventionmay be carried out without a solvent, or it may be radicalpolymerization using an organic solvent or water as a medium. An organicsolvent is not specifically limited as long as it permits radicalpolymerization and does not impair the function as a RAFT agent bychemically changing a compound of the present invention.

In radical polymerization using a compound of the present invention, avinyl monomer may be added dropwise to the polymerization system duringradical polymerization, or radical polymerization may be carried outwith batchwise addition.

When emulsion polymerization is carried out using a compound of thepresent invention, it may be preferred to prepare, before the additionof a vinyl monomer, an aqueous solution in which a compound of thepresent invention and an emulsifying agent has been mixed. By mixingbefore the addition of a vinyl monomer, a mixed micelle can be formedcomprising the emulsifying agent and the compound of the presentinvention in an aqueous solution. After or during adding a vinylmonomer, or when vinyl monomer is added in a mixture, the compound ofthe present invention may be estimated to be incorporated preferentiallyin the vinyl monomer due to the problem of compatibility of the vinylmonomer and the compound of the present invention, and radicalpolymerization may proceed in a polymerization mechanism similar to acommon radical mass polymerization.

Also, in radical polymerization using a compound of the presentinvention, synthesis of a block copolymer which is characteristic ofcontrolled radical polymerization can be effected. In order to obtain ablock copolymer, a second vinyl monomer may be added after thepolymerization of a first vinyl monomer and polymerized to synthesize adiblock copolymer. Furthermore, after the polymerization of a secondvinyl monomer, a third vinyl monomer may be added and polymerized tosynthesize a triblock copolymer, and by further adding and polymerizinganother vinyl monomer, a multiblock copolymer may also be synthesized.As a method for synthesizing a block copolymer, there can be mentioned,for example, a method in which each vinyl monomer may be added dropwisewhile adjusting the dropping speed thereof, and a method in which theymay be added batchwise to form latex and then to initiatepolymerization. Also, by using a mixture of different monomers as afirst vinyl monomer, a copolymer block part derived from the first vinylmonomer may be a random copolymer part in which different first vinylmonomers are randomly polymerized with each other. Similarly, by using amixture of different monomers as a second or third vinyl monomer, acopolymer block part derived from the second or third vinyl monomer maybe a random copolymer part in which different second or third vinylmonomers are randomly polymerized with each other.

At this time, for stabilization of latex, the above emulsifying agentand dispersant other than the RAFT agent of the compound of the presentinvention may be added. Also, when a radical initiator is not present inthe polymerization system, a radical initiator must be added to restartradical polymerization.

Also in polymerization using a compound of the present invention, acrosslinking monomer may be added as needed. For example, in order toconfer rubber elasticity to the polymer obtained, n-butyl acrylate maybe copolymerized with a small amount of allyl methacrylate, andpolyethylene glycol, polypropylene glycol, polybutyleneglycol or thelike having (meth)acrylate groups on both ends, and then methylmethacrylate may be polymerized, and thereby it is possible to adjustthe polymerization process so as to assume a core-shell structure inwhich a core of n-butyl acrylate that polymerized while beingcrosslinked and its outer layer are coated with a polymer of methylmethacrylate as a shell.

As a method of recovering the polymer as powder from the polymer latexproduced by the emulsion polymerization process, a method in which aftera coagulation step in which the polymer latex is contacted with anaqueous coagulant solution and coagulated, it is washed with about 1-100parts by weight of water, followed by a dehydration treatment such asfiltration to prepare a wet powder, and further the wet powder is driedwith a pressure dehydrator or a hot-air drier such as a fluidized driermay be preferred. The drying temperature and drying time at this timemay be decided as appropriate depending on the type of the polymer.

As a coagulating agent to be used in the coagulation step, there can bementioned, for example, a calcium salt such as calcium acetate andcalcium chloride. When the polymer is an acrylic resin, it maypreferably be calcium acetate, since in this case the formed bodyobtained has excellent anti-hot water whitening and the water content ofthe powder recovered may be reduced. The coagulant may be used alone ortwo or more of them may be used in combination.

The coagulant may be used as an aqueous solution. The concentration ofan aqueous coagulant solution may preferably be 0.1% by weight or more,and more preferably 1% by weight or more, since it enables to stablycoagulate and recover the polymer. Also, the concentration of an aqueouscoagulant solution may preferably be 20% by weight or less, and morepreferably 15% by weight or less, since it enables to reduce the amountof residual coagulant in the recovered polymer and gives an excellentanti-hot air whitening of the formed body obtained.

The amount of an aqueous coagulant solution used in the coagulation stepmay preferably be 10 parts by weight or more relative to 100 parts byweight of the polymer latex, and 500 parts by weight or less relative to100 parts by weight of the polymer latex.

The temperature during the coagulation step may preferably be 30° C. ormore and 100° C. or less. The contact time is not specifically limited.

Before recovering the polymer as a powder from the polymer latex, thepolymer latex may be treated as needed with a filtering device chargedwith a filter material. The filtration treatment intends to removescales produced during polymerization from the polymer latex, to removecontaminants, from the polymer latex, that entered into thepolymerization feed or into the polymerization step from outside, andmay be preferred in terms of forming a good formed body using a powderrecovered from the polymer latex.

As a filtering device charged with a filter material, there can bementioned one that employs a saclike mesh filter, a centrifuge-typefiltering device that has a cylindrical filter material in the insidesurface of a cylindrical filtering chamber and has stirring bladesplaced in the filtering material, and a filtering device in which ahorizontally placed filter material moves in a horizontal circularmotion and a vertical reciprocal motion with the surface of the filtermaterial as the base. Among them, a filter device in which ahorizontally placed filter material moves in a horizontal circularmotion and vertical reciprocal motion may be preferred.

In the case of radical polymerization using an organic solvent, a knownmethod of recovering a polymer can be used. Generally a method in whicha polymer solution is added to a solvent in which the polymer obtainedis insoluble, and the polymer is precipitated and recovered is known.

The polymer obtained in the above method has a functional group derivedfrom a RAFT agent represented by the following general formula (3) or(4) at the end. Hereinafter this may be referred to as a “RAFT agentend.” RAFT agent ends can be removed from the polymer obtained bytreatment with an organic peroxide, a persulfate or an azo compound.

As an organic peroxide, a persulfate or an azo compound, there can bementioned compounds illustrated as specific examples of the radicalpolymerization initiator.

By the elimination reaction of the RAFT agent end, a structure unitrepresented by the following general formula (3) or (4) can be removedfrom the polymer end.

wherein, R¹ and R³ each represent an organic group having ahydrophile-lipophile balance (HLB) determined by Griffin's method of 3or more,

Z represents a nitrogen atom, an oxygen atom, a sulfur atom, a methylenegroup, or an unsubstituted aromatic hydrocarbon group,

R¹ represents, when Z is other than a sulfur atom, a monovalent organicgroup having one or more carbons, and said monovalent organic group maycomprise at least one of a nitrogen atom, an oxygen atom, a sulfur atom,a halogen atom, a silicon atom and a phosphorous atom and may representa high molecular weight substance,

R¹ represents, when Z is a sulfur atom, a monovalent aliphatichydrocarbon group or aromatic hydrocarbon group having one or morecarbons that bind(s) to the sulfur atom at a primary carbon, and saidmonovalent hydrocarbon group may comprise at least one of a nitrogenatom, an oxygen atom, a sulfur atom, a halogen atom, a silicon atom anda phosphorous atom, or may represent a high molecular weight substance;

R³ represents, when Z is other than a sulfur atom, a q-valent organicgroup having one or more carbons, and said q-valent organic group maycomprise at least one of a nitrogen atom, an oxygen atom, a sulfur atom,a halogen atom, a silicon atom and a phosphorous atom, or may representa high molecular weight substance, and

R³ represents, when Z is a sulfur atom, a monovalent aliphatichydrocarbon group or aromatic hydrocarbon group having one or morecarbons that bind(s) to the sulfur atom at a primary carbon; and q is aninteger of 2 or more.

In order to allow the above compound to react with a RAFT agent-endedpolymer, it is necessary to carry out the reaction at a temperature thatallows the above compound to produce a radical. The temperature forproducing a radical may be determined as appropriate depending on thecompound used, and generally a half-life temperature of the abovecompound may be referred to, and may preferably be reacted at atemperature higher than that.

In addition to the above organic peroxide, persulfate, or azo compound,there can be used an oxidant such as m-chloroperbenzoic acid and sodiumhypochlorite, or a nucleophilic reagent such as ammonium, a primaryamine and a secondary amine.

By an elimination reaction of the RAFT agent end, when a nucleophilicreagent such as an oxidant and an amine is used, a structure unitrepresented by the following general formula (5) or (6) can be removedfrom the polymer end.

wherein, R¹ and R³ each represent an organic group having ahydrophile-lipophile balance (HLB) determined by Griffin's method of 3or more,

Z represents a nitrogen atom, an oxygen atom, a sulfur atom, a methylenegroup, or an unsubstituted aromatic hydrocarbon group,

R¹ represents, when Z is other than a sulfur atom, a monovalent organicgroup having one or more carbons, and said monovalent organic group maycomprise at least one of a nitrogen atom, an oxygen atom, a sulfur atom,a halogen atom, a silicon atom and a phosphorous atom and may representa high molecular weight substance,

R¹ represents, when Z is a sulfur atom, a monovalent aliphatichydrocarbon group or aromatic hydrocarbon group having one or morecarbons that bind(s) to the sulfur atom at a primary carbon, and saidmonovalent hydrocarbon group may comprise at least one of a nitrogenatom, an oxygen atom, a sulfur atom, a halogen atom, a silicon atom anda phosphorous atom, or may represent a high molecular weight substance;

R³ represents, when Z is other than a sulfur atom, a q-valent organicgroup having one or more carbons, and said q-valent organic group maycomprise at least one of a nitrogen atom, an oxygen atom, a sulfur atom,a halogen atom, a silicon atom and a phosphorous atom, or may representa high molecular weight substance, and

R³ represents, when Z is a sulfur atom, a monovalent aliphatichydrocarbon group or aromatic hydrocarbon group having one or morecarbons that bind(s) to the sulfur atom at a primary carbon; and q is aninteger of 2 or more.

The temperature at which the above compound is reacted to a RAFTagent-ended polymer may be determined as appropriate depending on thecompound used, and generally may preferably be reacted at a temperaturelower than the boiling point of the above compound.

The amount of an organic peroxide, a persulfate, an azo compound, anoxidant or a nucleophilic reagent to be used in the above method mayaffect the structure of the end of the polymer from which the RAFT agentend has been removed. When, relative to the amount of the RAFT agent endcontained in the polymer, an equal or a smaller amount of the compoundis used, a polymer having residual RAFT agent end can be obtained. Inorder to obtain a polymer in which the RAFT agent end has been removed,an equal amount to about 20-fold amount may preferably be added, and a10-fold to 20-fold amount may be more preferred.

Thus, the structure of the end of the polymer in which the RAFT agentend has been removed by the above method may be different depending onthe compound to be reacted.

When an organic peroxide, a persulfate or an azo compound is used, thestructure of the end of the polymer may differ with the amount of theorganic peroxide, the persulfate or the azo compound to be used. Forexample, an equal amount to about 10-fold amount the number of end ofthe polymer is used, it is known, double bonds may be formed at the endof the polymer after the RAFT agent end has been removed. When an about10-fold to 20-fold amount is used, a polymer having no double bond atthe end can be obtained by binding a radical at the end of the polymerobtained by removing the RAFT agent end and a end radical derived fromthe decomposition of an organic peroxide, a persulfate or an azocompound.

Details are described in Perrier et al.'s paper (Macromolecules, 2006,vol. 38, pp. 2033).

When a nucleophilic reagent such as an oxidizing agent and an amine isused, a polymer having a thiol group at the end can be obtained by usingan equal amount to about 10-fold amount the number of end of thepolymer. Using this thiol group, a ene-thiol reaction may be carried outor the metal surface and the thiol group at the end of the polymer maybe reacted to prepare an organic/inorganic complex.

As a process for removing a RAFT agent end from a RAFT agent-endedpolymer of the present invention, there can be mentioned a process of,after emulsion polymerization, recovering a powder of the RAFTagent-ended polymer using the above recovery method, then redissolvingin a solvent, and adding an organic peroxide, a persulfate, an azocompound, an oxidizing agent, or a nucleophilic reagent to remove theRAFT agent end, a process of, after emulsion polymerization, adding theabove compound to the system without recovering the polymer thereby toremove the RAFT agent end, and the like. Among them, for the ease of theprocess, the process of adding the above compound to the system withoutrecovering the polymer after emulsion polymerization may be preferred.

When the RAFT agent end was removed from the polymer by conductingpolymerization using any of (RAFT-1), (RAFT-2), (RAFT-5), (RAFT-6) and(RAFT-7) and acting an azo compound 2,2′-azobisisobutyronitrile (AIBN)thereon, the RAFT agent eliminated from the polymer has a structureidentical with any of (RAFT-1), (RAFT-2), and (RAFT-5) to (RAFT-7).Thus, it is also possible to recover the eliminated RAFT agent afterremoving the RAFT agent from the polymer, and to reuse it.

As a method for recovering the eliminated RAFT agent after removing theRAFT agent from the polymer, there can be mentioned a method in which,after emulsion polymerization, the RAFT agent is removed from thepolymer, the polymer is recovered by coagulating it, and the RAFT agentis recovered with an organic solvent from an aqueous solution used forcoagulation after recovering the polymer. The RAFT agent thus recoveredcan be reused as long as it does not affect the polymerizationcontrolling ability.

The thermoplastic resin composition of the present invention maycomprise the polymer of the present invention, and as needed may beblended with another polymer material. Also, as needed, various knownadditives such as a lubricant, an antiblocking agent, a UV absorber, aphotostabilizer, a plasticizer (phthalate, etc.), a stabilizer(2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenylacrylate,etc.), a colorant (chrome orange, titanium oxide, etc.), a filler(calcium carbonate, clay, talc, etc.), an antioxidant (alkylphenol, anorganic phosphite, etc.), a UV absorber (salicylate, benzotriazole,etc.), a fire retardant (a phosphate, antimony oxide, etc.), anantistatic, a lubricant, a foaming agent, and anantibacterial/antifungal agent may be added. The amount blended thereofmay be determined as appropriate depending on the intended use. Knownmethods of blending can be used. For example, a mill roll, a Banburymixer, a super mixer, a monoaxial or biaxial extruder, etc., may be usedin mixing and kneading.

The thermoplastic resin composition of the present invention may beformed by a known molding method such as injection, melt extrusion andcalendering. The forming temperature may be selected, as appropriate,depending on the thermal stability and molecular weight of thethermoplastic resin obtained, and may generally be formed at atemperature higher than the glass transition temperature of thethermoplastic resin.

The copolymer of the present invention may be useful as a thermoplasticresin composition, a thermal or light setting resin composition, amordant resin composition and an adhesive resin composition making useof the fact that it is a block copolymer. The formed body of the presentinvention may be useful as a forming material such as film and sheet.

In addition to this, it is also possible to dissolve it in an organicsolvent to form a film by the spincoat method or a solvent cast method.

It is also possible to use the thermoplastic resin composition of thepresent invention as a constituent of a resin composition for coatingmaterial. A coating material for a resin composition may be mixed withan organic solvent or may be constituted with solid components alonewithout using an organic solvent. The copolymer of the present inventionan organic solvent and, as needed, various additives may be blended by aknown method. In order to enhance a coating property, the resincomposition for coating material may preferably be blended, as needed,with an organic solvent in which the thermoplastic resin of the presentinvention and, as needed, various additives are soluble.

As an organic solvent, there can be mentioned aromatic hydrocarbons suchas toluene, xylene, “Swasol #1000” (trade name, manufactured by MaruzenPetrochemical Co., Ltd.), “Solvesso “150” (trade name, Exxon ChemicalsCo., Ltd.) and “Supersol 1500” (trade name, manufactured by NipponPetrochemicals Co., Ltd.); ketones such as methylethylketone andmethylisobutylketone; esters such as ethyl acetate, n-butyl acetate,propyleneglycol monomethyletheracetate, “DBE” (trade name, manufacturedby DuPont K.K.); alcohols such as n-butanol and isopropyl alcohol;glycol solvents such as ethyleneglycol monobutylether. Among theseorganic solvents, aromatic hydrocarbons may specifically be preferredbecause of their excellent workability. The organic solvent may be usedalone or two or more of them may be used in combination.

When the thermoplastic resin composition of the present inventioncomprises hydroxyl group-containing monomer units, solvent resistance,water resistance, and weather resistance of coating film obtained can beenhanced by blending a melamine resin or an isocyanate compound as acrosslinking component to the resin composition for coating material.

As a specific example of the melamine resin, there can be mentioned an-butylated melamine resin and a methylated melamine resin.

As an isocyanate compound, a polyisocyanate compound having a freeisocyanate group and a blocked polyisocyanate compound may be mentioned.As specific examples, there can be mentioned aliphatic diisocyanatessuch as hexamethylene diisocyanate; cyclic aliphatic diisocyanates suchas 4,4′-methylenebis(cyclohexylisocyanate); aromatic diisocyanates suchas tolylene diisocyanate; adducts of an excess amount of saiddiisocyanate and a polyhydric alcohol or water; and polymers and biuretform of said diisocyanates.

An isocyanate compound may be blended with a monomer unit having ahydroxy group in a block copolymer at an equivalent ratio ofNCO/OH=0.1/1 to 3/1.

Other examples of various additives include, for example, a gloss agentsuch as aluminum paste and mica; various stabilizing agents such as anantioxidant, a UV absorber, an anti-weather agent, an anti-radiationagent, and a thermal stabilizing agent; a coloring agent such as aninorganic pigment, an organic pigment and a dye; aconductivity-imparting agent such as carbon black and ferrite; anon-acrylic resin such as an inorganic filler, a lubricant, aplasticizer, an organic peroxide, a neutralizing agent, an alkyd resin,an epoxy resin, and a fibrinogen resin; and an auxiliary additive suchas a surface-controlling agent, a curing catalyst, and a pigmentsedimentation-preventing agent.

A resin composition for coating material can be coated by a knownmethod. For example, there can be mentioned a method in which a resincomposition for coating material or a resin composition for coatingmaterial to which an organic solvent has been added may be coated byblowing it to the substrate surface to a film thickness after drying ofabout 1-80 μm using a spray gun etc.

EXAMPLES

The present invention will now be explained in further details withreference to synthetic examples, Working Examples and ComparativeExamples, but the present invention is not limited to these examples inany way. “Parts” and “%” in the examples refer to “parts by weight” and“% by weight,” respectively.

1. Gas Chromatography (GC) Analysis

GC analysis was carried out under the following analytic condition, andfrom the peak area ratio, the purity of the RAFT agent and a precursorthereof and the concentration of impurities were determined.

Column: Capillary column DB-1 (manufactured by GL Sciences Inc., columnlength: 30 m, column inner diameter: 0.53 mm, film thickness in thecapillary: 5 μm)

Carrier gas: Helium

Column temperature: 50° C. is maintained for 3 minutes, temperature isincreased at 10° C./min, and 220° C. is maintained for 10 minutes

Injection port temperature: 220° C.

Detector temperature: 220° C.

Detector: FID

2. Polymerization Conversion Ratio

The polymerization conversion ratio was calculated by measuring thesolid of latex. The solid was determined as follows:

In an aluminum cup, a solution after the desired period ofpolymerization time was weighed out, which was set as (y′), dried at 80°C. for 12 hours, and the weight of the solid was measured, which was setas (x′). From the ratio (x/y) of the total weight (x) of the vinylmonomer and the RAFT agent contained during polymerization and theweight (y) of the total feed, a theoretical solid when 100% waspolymerized was calculated, and from the ratio of the solid after drying(x′/y′) and (x/y), the polymerization conversion ratio was calculated.

Polymerization conversion ratio=100×{(x′/y′)/(x/y)}

3. The Number Average Molecular Weight and Molecular Weight Distributionof the Polymer

Number average molecular weight (Mn), weight average molecular weight(Mw) and molecular weight distribution (Mw/Mn) were determined by gelpermeation chromatography (GPC) with methyl polymethacrylate as thestandard.

Instrument: HLC-8220 (manufactured by Tosoh Corp.)

Column: TSK GUARD COLUMN SUPER HZ-L (manufactured by Tosoh Corp., 4.6×35mm), TSK-GEL SUPER HZM-N (manufactured by Tosoh Corp., 6.0×150 mm)×2connected in series

Eluent: Chloroform

Measuring temperature: 40° C.

Flow rate: 0.6 mL/min

4. Identification of Compound and Confirmation of the presence of an endRAFT agent For measurement, ¹H-NMR (manufactured by Jeol Ltd.,JNM-EX270) was used.

The compound was dissolved in deuterated chloroform, andtetramethoxysilane in deuterated chloroform was used as an internalstandard. The measuring temperature was 25° C. and the number ofaddition was 16.

For the polymer after the end treatment step, the polymer was dissolvedin deuterated chloroform, and using tetramethoxysilane in deuteratedchloroform as an internal standard, the presence of the RAFT agent wasconfirmed from the presence of aromatic peaks derived from the RAFTagent.

Working Example 1 Synthesis of Polyethylene Glycol (PEG)-RAFT-1

In a 200 ml round-bottomed flask, 17.3 g (100 mmol) of 4-bromophenol,0.01 g of p-toluenesulfonic acid monohydrate, and 100 ml ofdichloromethane were introduced. After cooling to 0° C., 9.25 g (110mmol) of dihydropyran (DHP) was added dropwise. After stirring for 3hours, the reaction mixture was concentrated, and purified by silica gelchromatography (eluted with a mixed solvent of ethylacetate:n-hexane=1:5 (vol/vol)) to obtain 21.3 g of2-(4-bromophenoxy)tetrahydro-2H-pyran (precursor A) (yield: 83.0%).

Then, into a 500 ml four-mouth flask equipped with a condenser and athermometer, 1.95 g (80 mmol) of magnesium, 100 ml of dehydratedtetrahydrofuran (THF) and 0.02 g of iodine were introduced. Then, adropping funnel containing 20.6 g (80 mmol) of previously synthesizedprecursor A and another dropping funnel containing 14.2 g (88 mmol byassuming a purity of 92%) of bromoisobutyronitrile were prepared, andthe inside of the reaction system was replaced with argon. 20-30% of theprecursor A was introduced at room temperature, and after starting theGrignard reaction, the remaining precursor A was added dropwise whilemaintaining the reaction temperature at 50-60° C.

After the dropwise addition was over and stirring at 35-40° C. for 1hour, 6.70 g (88 mmol) of carbon bisulfide was added dropwise whilekeeping the inner temperature at 45° C. or less. After the dropwiseaddition was over, temperature was maintained at 38-40° C. for 1 hour,and then bromoisobutyronitrile was slowly added dropwise. After thedropwise addition was over, the temperature of the reaction mixture wasincreased to 56° C. and stirring was continued for 72 hours.

72 hours later, ice water was introduced into the reaction mixture, andafter evaporating THF under reduced pressure from the reaction mixture,the reaction mixture was extracted twice with 200 ml of diethylether.The extract was dried with magnesium sulfate, and then concentrated. Tothe crude product obtained, 100 ml of THF was added. After cooling to 0°C., 0.1 ml of 3.6% hydrochloric acid was added and continued to stiruntil tetrahydropyranylether was deprotected. After the reaction wasover, sodium carbonate was added to the reaction mixture to neutralizehydrochloric acid and concentrated. By purifying by silica gelchromatography (eluted with a mixed solvent of ethylacetate:n-hexane=1:5 (vol/vol)), 10.6 g of2-cyanoprop-2-yl-(4-hydroxy)dithiobenzoate (precursor B) was obtained(yield: 55.7%).

To a round-bottomed flask equipped with a condenser, 45 g (60 mmol) ofPEG monomethylether of Mn 750, 20 g of pyridine and 200 g of toluenewere added, and after adding 30 g (300 mmol) of succinic anhydride wasadded, it was heated to 80° C. and reacted for 72 hours. Seventy twohours later, the reaction mixture was cooled, and the unreacted succinicanhydride that deposited was filtered off. Then, water was added to theresidue obtained by evaporating toluene and pyridine under reducedpressure, insoluble matters were filtered off. After the procedure ofconcentrating the filtrate under reduced pressure and then adding waterto concentrate again was carried out for a total of 3 times, toluene wasadded to the residue to remove residual water by azeotropicdistillation, and thus 50 g of crude monomethoxypolyethylene glycolsuccinate ester (precursor C) was obtained.

4.00 g (4.7 mmol) of precursor C and 1.13 g (4.7 mmol) of previouslysynthesized precursor B were dissolved in 10 g of dichloromethane, towhich 1.1 g (5.3 mmol) of N,N′-dicyclohexylcarbodiimide and 0.1 g ofN,N-dimethylaminopyridine were added and then reacted at 50-55° C. for48 hours.

Forty eight hours later, the reaction mixture was cooled to roomtemperature, and the solid deposited was filtered off. Afterconcentrating the filtrate, a mixed solvent of n-hexane:diethylether=1:1was added. After stirring for about 30 minutes at room temperature andallowing to stand, the supernatant was decanted. The residue wasconcentrated under reduced pressure to obtain 4.7 g of PEG-RAFT-1(yield: 92.0%).

¹H-NMR (CDCl₃): δ (ppm): 1.94 (s, 6H), 2.79 (t, 2H), 2.90 (t, 2H), 3.38(s, 3H), 3.63 (s, 62H), 4.27 (t, 2H), 7.15 (d, 2H), 7.96 (d, 2H)

The HLB value of R¹ of this PEG-RAFT-1 was about 17.3, and the HLB valueof the PEG-RAFT-1 as a whole was about 13.8.

Working Example 2 Synthesis of PEG-RAFT-2

In a manner similar to Working Example 1 except that PEG monomethyletherof Mn 2000 was used, PEG-RAFT-2 was obtained (yield: 89.0%).

The result of ¹H-NMR was almost identical with the spectrum ofPEG-RAFT-1 except that the integrated intensity of the peak observed atabout 3.63 ppm was different. The HLB value of R¹ of this PEG-RAFT-2 wasabout 18.9, and the HLB value of the PEG-RAFT-2 as a whole was about17.1.

Working Example 3 Synthesis of PEG-RAFT-3

In a manner similar to Working Example 1, except that PEGmonomethylether of Mn 5000 was used, PEG-RAFT-3 was obtained (yield:78.5%).

The result of ¹H-NMR was almost identical with the spectrum ofPEG-RAFT-1 except that the integrated intensity of the peak observed atabout 3.63 ppm was different. The HLB value of R¹ of this PEG-RAFT-3 wasabout 19.5, and the HLB value of the PEG-RAFT-3 as a whole was about18.7.

Working Example 4 Synthesis of anionic RAFT-1

In a 200 ml round-bottomed flask, 10.9 g (50 mmol) of2-(4-bromophenoxy)ethanol, 0.01 g of p-toluenesulfonic acid monohydrate,and 50 ml of dichloromethane were introduced. After cooling to 0° C.,4.63 g (55 mmol) of DHP was added dropwise. After stirring for 3 hours,the reaction mixture was concentrated, and purified by silica gelchromatography (eluted with a mixed solvent of ethylacetate:n-hexane=1:5 (vol/vol)) to obtain 13.7 g of2-(4-bromophenoxy)ethoxy)tetrahydro-2H-pyran (precursor D) (yield:91.0%).

Then, into a 200 ml four-mouth flask equipped with a condenser and athermometer, 0.97 g (40 mmol) of magnesium, 30 ml of dehydrated THF and0.01 g of iodine were introduced. A dropping funnel containing 12.0 g(40 mmol) of previously synthesized precursor D and another droppingfunnel containing 7.07 g (44 mmol by assuming a purity of 92%) ofbromoisobutyronitrile were prepared, and the atmosphere in the reactionsystem was replaced with argon. After adding dropwise precursor D whilemaintaining the reaction mixture at 50-60° C., it was stirred at 35-40°C. for 1 hour, and 3.35 g (44 mmol) of carbon bisulfide was addeddropwise while keeping the inner temperature at 45° C. or less.

After the dropwise addition was over, temperature was maintained at38-40° C. for 1 hour, and bromoisobutyronitrile was added dropwise.After the dropwise addition was over, the reaction temperature wasincreased to 56° C. and stirring was continued for 72 hours. Seventy twohours later, ice water was introduced into the reaction mixture, whichwas then concentrated and extracted twice with 200 ml of diethylether.The extract was dried with magnesium sulfate, then concentrated, and 200ml of ethanol was added to the residue. After cooling to 0° C., 0.1 mlof 3.6% hydrochloric acid was added and continued to stir untiltetrahydropyranylether was deprotected. After the reaction was over, thereaction mixture was concentrated, and purified by silica gelchromatography (eluted with a mixed solvent of ethylacetate:n-hexane=1:1 (vol/vol)) to obtain 10.2 g of2-cyanoprop-2-yl-{4-(2-hydroxy-ethoxy)}dithiobenzoate (precursor E)(yield: 91%).

To a round-bottomed flask, 1.16 g (4 mmol) of precursor E, 20 ml of THF,10 ml of triethylamine and 0.4 g (4 mmol) of succinic anhydride wereadded, and reacted for 1 hour. One hour later, to this solution anaqueous solution having 0.4 g (4 mmol) of potassium bicarbonatedissolved in 5 ml of water was added. After stirring for 1 hour, thesolvent was evaporated under reduced pressure. The residue was dissolvedin 10 ml of water, and after extracting twice with 10 ml of ethylacetate, the aqueous layer was taken out, and the solvent was evaporatedunder reduced pressure to obtain 1.34 g (3.2 mmol) of anionic RAFT-1(yield: 79.8%).

¹H-NMR (D₂O): δ (ppm): (s, 6H), (t, 2H), (t, 2H), (t, 2H), (t, 2H), (d,2H), (d, 2H)

The HLB value of R¹ of this anionic-RAFT-1 was about 8.3(83.011/199.13), and the HLB value of the anionic-RAFT-1 as a whole wasabout 4.0.

Synthetic Example 1 Synthesis of RAFT-1

Into a 3000 ml four-mouth flask equipped with a condenser and athermometer, 1790 g of carbon tetrachloride, 275 g (1.5 mol) ofN-bromosuccinimide (NBS), 121.9 g (1.75 mol) of isobutyronitrile, and3.75 g of AIBN were introduced, and the bath temperature was raised to85° C. with an oil bath. After refluxing for 10 hours, the reactionmixture was cooled, the filtrate from which succinimide was removed waswashed with a 10% aqueous solution of sodium bisulfite, and afterfurther washing with water, dried with magnesium sulfate. Afterfiltrating off the magnesium sulfate, a 102-130° C. fraction wasaliquoted to obtain bromoisobutyronitrile.

Then, into a 2000 ml four-mouth flask equipped with a condenser and athermometer, 24.3 g (1.0 mol) of magnesium, 750 ml of dehydrated THF and0.1 g of iodine were introduced. Then, a dropping funnel containing 158g (1.0 mmol) of bromobenzene and another dropping funnel containing 161g (1.0 mmol by assuming a purity of 92%) of previously synthesizedbromoisobutyronitrile were prepared, and the atmosphere in the reactionsystem was replaced with argon. After adding dropwise bromobenzene whilemaintaining the reaction mixture at 40° C., it was stirred at 37-40° C.for 1 hour, and 61 ml (1.0 mol) of carbon bisulfide was added dropwiseat the inner temperature of 42° C. or less. After the dropwise additionwas over and maintaining at 38-40° C. for 1 hour, bromoisobutyronitrilewas added. After the dropwise addition was over, the reactiontemperature was raised to 56° C., and stirring was continued for 24hours.

Twenty four hours later, ice water was introduced into the reactionmixture, which was then concentrated and extracted twice with 1500 ml ofdiethylether. The extract was dried with magnesium sulfate, thenconcentrated, and purified by silica gel chromatography (using silicagel of 10-fold amount that of the crude product, eluted with a mixedsolvent of ethyl acetate:n-hexane=1:20 (vol/vol)) to obtain 162.5 g ofcyanoisopropyl dithiobenzoate (C₆H₅—C(S)S—C(CN)(CH₃)₂: RAFT-1) (yield:72%).

Identification was carried out using ¹H NMR, and assignment was made byreferring to the values described in a reference (Polym. Int., 2000,Vol. 49, pp. 933-1001). Since corresponding to R¹ of this RAFT-1 ishydrogen atom (H—), and the HLB value becomes 0, RAFT-1 does notcorrespond to the compound of the present invention.

Synthetic Example 2 Synthesis of RAFT-2

Synthesis was carried out by referring to Rizzardo et al.'s paper(Macromolecules, 2007, Vol. 40, pp. 4446).

To 1000 ml of a diethylether solution in which 146 g (0.49 mol) of thepreviously synthesized sodium salt of n-dodecyl trithiocarbonate wasdispersed, 63 g (0.25 mol) of iodine was added, stirred at roomtemperature for 1 hour, and sodium iodide produced was removed byfiltration. An excess iodine was removed by washing with sodiumthiosulfate, and after drying with magnesium sulfate, it wasconcentrated to obtain 120 g of a brown mixture.

After this mixture was dissolved in 1000 ml of ethyl acetate, 70 g (0.25mol) of 4,4′-(4-cyanopentanoic acid) was added and refluxed for 24hours. After evaporating the solvent, it was washed with hexane todissolve the compound of interest. This solution was purified by silicagel chromatography (using silica gel of 10-fold amount that of the crudeproduct, eluted with a mixed solvent of n-hexane:ethyl acetate=1:50(vol/vol)) to obtain 89.2 g of C₁₂H₂₅—SC(S)S—C(CN)(CH₃)CH₂CH₂COOH:RAFT-2) (yield: 49%).

Identification of the compound was carried out based on the assignmentdescribed in the above reference. The HLB value of dodecyl group(C₁₂H₂₅—) corresponding to R¹ of this RAFT-1 is 0.

Working Example 5 Emulsion Polymerization of Methyl Methacrylate (MMA)Using PEG-RAFT-1-1

Into a separable flask equipped with a condenser and a stirrer unit,2.85 parts of an anionic emulsifying agent (manufactured by Kao Corp.,Pelex O-TP) and 1500 parts of distilled water were introduced, to which1.67 part of PEG-RAFT-1 obtained in Working Example 1 was added andstirred at room temperature for 30 minutes. Then, 500 parts of MMA wasadded, and, in a nitrogen atmosphere, heated in a water bath to 80° C.under stirring. After raising the temperature to 80° C., an aqueoussolution prepared by dissolving 0.5 part of potassium persulfate in 25parts of distilled water was added in one motion, and then samples werecollected at the desired times while stirring.

In the present Working Example, the ratio of the molar concentration ofMMA and that of PEG-RAFT-1, i.e. [MMA]/[PEG-RAFT-1], is 3000 and atheoretical Mn when 100% of MMA was polymerized is about 300,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 5.

Working Example 6 Emulsion Polymerization of MMA Using PEG-RAFT-1-2

In a manner similar to Working Example 5, except that 8.33 parts ofPEG-RAFT-1 in stead of 1.67 part was used, MMA was emulsion polymerized.

[MMA]/[PEG-RAFT-1] of the present Working Example is 600, and atheoretical Mn when 100% of MMA was polymerized is about 60,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 5.

Working Example 7 Emulsion Polymerization of MMA Using PEG-RAFT-1-3

In a manner similar to Working Example 5, except that the polymerizationtemperature was set at 50° C. in stead of 80° C. and 5.85 parts of anonionic emulsifying agent (manufactured by Kao Corp., Emalgen 147) instead of 2.85 parts of an anionic emulsifying agent (manufactured by KaoCorp., Pelex O-TP) was used, MMA was emulsion polymerized.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 6.

Working Example 8 Emulsion Polymerization of MMA Using PEG-RAFT-2-1

In a manner similar to Working Example 7, except that PEG-RAFT-2 (3.76parts) synthesized in Working Example 2 in stead of PEG-RAFT-1 (1.67part) was used, MMA was emulsion polymerized.

[MMA]/[PEG-RAFT-2] of the present Working Example is 3000, and atheoretical Mn when 100% of MMA was polymerized is about 300,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 6.

Working Example 9 Emulsion Polymerization of MMA Using PEG-RAFT-3-1

In a manner similar to Working Example 7, except that PEG-RAFT-3 (8.77parts) synthesized in Working Example 3 in stead of PEG-RAFT-1 (1.67part) was used, MMA was emulsion polymerized.

[MMA]/[PEG-RAFT-3] of the present Working Example is 3000, and atheoretical Mn when 100% of MMA was polymerized is about 300,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 6.

Comparative Example 1 Emulsion Polymerization of MMA Using RAFT-1-1

In a manner similar to Working Example 5, except that RAFT-1 (0.35 part)synthesized in Synthetic Example 1 in stead of PEG-RAFT-1 (1.67 part)was used, MMA was emulsion polymerized.

[MMA]/[RAFT-1] of the present Comparative Example is 3000, and atheoretical Mn when 100% of MMA was polymerized is about 300,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 7.

Comparative Example 2 Emulsion Polymerization of MMA Using RAFT-1-2

In a manner similar to Working Example 6, except that RAFT-1 (1.76 part)synthesized in Synthetic Example 1 in stead of PEG-RAFT-1 (8.33 parts)was used, MMA was emulsion polymerized.

[MMA]/[RAFT-1] of the present Comparative Example is 600, and atheoretical Mn when 100% of MMA was polymerized is about 60,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 7.

Comparative Example 3 Emulsion Polymerization of MMA Using RAFT-2-1

In a manner similar to Working Example 5, except that RAFT-2 (0.70 part)synthesized in Synthetic Example 2 in stead of PEG-RAFT-1 (1.67 part)was used, MMA was emulsion polymerized.

[MMA]/[RAFT-2] of the present Comparative Example is 3000, and atheoretical Mn when 100% of MMA was polymerized is about 300,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 7.

Comparative Example 4 Emulsion Polymerization of MMA Using RAFT-2-2

In a manner similar to Working Example 6, except that RAFT-2 (3.49parts) synthesized in Synthetic Example 2 in stead of PEG-RAFT-1 (8.33parts) was used, MMA was emulsion polymerized.

[MMA]/[RAFT-2] of the present Comparative Example is 600, and atheoretical Mn when 100% of MMA was polymerized is about 60,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 7.

Working Example 10 Emulsion Polymerization of MMA Using PEG-RAFT-1-4

In a manner similar to Working Example 7, except that the amount ofPEG-RAFT-1 used was 11.9 parts and PEG-RAFT-1 previously dissolved inMMA was introduced in a separable flask, MMA was emulsion polymerized.

[MMA]/[PEG-RAFT-1] of the present Working Example is 420, and atheoretical Mn when 100% of MMA was polymerized is about 42,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 8.

Comparative Example 5 Emulsion Polymerization of MMA Using RAFT-1-3

In a manner similar to Working Example 10 except that 2.49 parts ofRAFT-1 synthesized in Synthetic Example 1 in stead of 11.9 parts ofPEG-RAFT-1 was added, MMA was emulsion polymerized.

[MMA]/[RAFT-1] of the present Comparative Example is 420, and atheoretical Mn when 100% of MMA was polymerized is about 42,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 8.

Working Example 11 Synthesis of MMA/n-butyl methacrylate (BMA) BlockCopolymer Using PEG-RAFT-1-1

Into a separable flask equipped with a condenser and a stirrer unit, 6.0parts of a nonionic emulsifying agent (manufactured by Kao Corp.,Emalgen 147) and 120 parts of distilled water were introduced, to which0.12 part of PEG-RAFT-1 obtained in Working Example 1, 0.3 part ofpotassium persulfate and 1.0 part of hexadecane as a dispersionassistant were added and stirred at room temperature for 30 minuteswhile purging with nitrogen. Then 15 parts of previously nitrogen-purgedMMA was added dropwise, and heated to 50° C. in a water bath whilestirring in a nitrogen atmosphere. Then samples were collected at thedesired times while stirring. After confirming that MMA was consumed, 15parts of previously nitrogen-purged BMA was added dropwise over 1.5hours.

After the dropwise addition was over, and further heating for 1 hour,the consumption of BMA was confirmed by analyzing with gaschromatography and ended.

In the present Working Example, the ratio of the concentration of MMAand BMA and that of PEG-RAFT-1, i.e., [MMA+BMA]/[PEG-RAFT-1], is 2100and a theoretical Mn when 100% of MMA and BMA was polymerized is about270,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. Mn was 280,000, Mw was360,000 and Mw/Mn was 1.31.

Comparative Example 6 Emulsion Polymerization of MMA Using Mercaptan-1

In a manner similar to Working Example 5, except that n-dodecylmercaptan (0.33 part) in stead of PEG-RAFT-1 (1.67 part) was used, MMAwas emulsion polymerized.

The solid of the samples collected every 10 minutes was measured, thepolymerization conversion ratio was determined, and Mn, Mw and Mw/Mn ofthe solid were determined by GPC. Polymerization was almost complete in30 minutes, and the polymerization conversion ratio after 30 minutes wasnot less than 90%. However, irrespective of the polymerization time andthe polymerization conversion ratio, Mn was about 100,000 and Mw/Mn wasabout 1.7, which were different from the behavior when controlledpolymerization was progressing.

Working Example 12 Removal of RAFT Agent End

From an aqueous solution of the polymer obtained in Working Example 5,1/10 was extracted, and to the extracted aqueous solution 0.27 part(10-fold equivalent relative to PEG-RAFT-1 end) of AIBN was added, andheated to 80° C. for 6 hours. Then, 200 parts of an aqueous solution inwhich calcium acetate was dissolved at 0.7% was warmed to 70° C. andstirred. Into this, an aqueous polymer solution was gradually addeddropwise to effect coagulation.

After the deposit was separated and washed, it was dried at 75° C. for24 hours to obtain a polymer. For the polymer obtained, the end wasexamined by NMR, and no aromatic peaks derived from the RAFT agent wereobserved at around 7.15 ppm and 7.96 ppm.

Comparative Example 7 Removal of RAFT Agent End

In a manner similar to Working Example 12, except that an aqueoussolution of the polymer obtained in Comparative Example 1 was used, theremoval of the AFT agent end was attempted. In a manner similar toWorking Example 12, the polymer was recovered by coagulation, and theend was examined by NMR. Aromatic peaks derived from the RAFT agent wereobserve at around 7.15 ppm and 7.96 ppm.

Working Example 13 Injection Molding of a Resin from which the RAFTAgent End has been Removed

By a compact injection molding instrument (model “CS-183-MMX”manufactured by Custom Scientific Instruments Inc.), the polymerobtained in Working Example 12 was injection molded at 240° C. to obtaina formed body. The formed body was colorless and transparent, and nofoaming was observed therein.

Comparative Example 8 Injection Molding of a resin Obtained Using RAFT-1

In a manner similar to Working Example 13, using a polymer recovered bycoagulation from an aqueous solution obtained in Comparative Example 7,a formed body was obtained. The formed body was yellow and air bubblesderived from foaming were observed.

Working Example 14 Synthesis of Anionic RAFT-2

Into a 100 ml round bottomed flask, 0.93 g (6.2 mmol) of adipic acid,1.4 g (5 mmol) of2-cyanopropyl-2-yl-{4-(2-hydroxy-ethoxy)}dithiobenzoate (precursor E)and 60 ml of toluene were introduced, and dehydrated while evaporatingtoluene under reduced pressure. After adding 30 ml of dehydratedmethylene chloride, 1.1 g (5.3 mmol) of dicyclohexyl carbodiimide and 50mg of dimethylaminopyridine were added and reacted at room temperaturefor 6 hours. After the dicyclohexyl urea produced as a byproduct wasfiltered off, the reaction mixture was washed with 1 normal hydrochloricacid, dried with sodium sulfate, then concentrated under reducedpressure, and purified by silica gel chromatography (eluted with a mixedsolvent of hexane:ethyl acetate=80:20 (vol/vol)) to obtain 1.6 g of2-cyanoprop-2-yl-[4-(2-(6-carboxypentanoyloxy)-ethoxyl]dithiobenzoate(anionic RAFT-2) (yield: 78%).

¹H-NMR (CDCl₃): 1.7 (ppm): (m, 4H), 1.9 (ppm): (s, 6H), 2.2 (ppm): (t,2H), 2.3 (ppm): (t, 2H), 4.2 (ppm): (t, 2H), 4.5 (ppm): (t, 2H), 6.8(ppm): (d, 2H), 7.9 (ppm): (d, 2H)

The HLB value of R¹ of this anionic RAFT-2 was about 7.31(83.111/227.284), and the HLB value of the anionic RAFT-2 as a whole wasabout 3.71.

Working Example 15 Synthesis of Anionic RAFT-3

Into a 300 ml round bottomed flask, 3.0 g (22 mmol) of potassiumcarbonate crushed in a mortar, 6.1 g (35 mmol) of 4-bromphenol and 16.5g (41 mmol) of 10-tetrapyranyloxy decanol p-toluenesulfonate were added,and, after adding 100 ml of acetone, was refluxed for 8 hours. Aftercooling to room temperature, water was added to end the reaction, andextracted twice with ethyl acetate. The ethyl acetate phase combined waswashed with saturated saline, dried with sodium sulfate, andconcentrated under reduced pressure. It was purified by columnchromatography (eluted with a mixed solvent of ethylacetate:n-hexane=20:80 (vol/vol)) using 300 g of silica gel to obtain8.85 g of 4-(10-tetrapyranyloxydecanonoxy)phenylbromide (precursor F)(yield: 43%).

In a manner similar to Working Example 4, except that 7.4 g (18 mmol) ofthe precursor F obtained was used, a Grignard reaction was carried outat from room temperature to 86° C. After cooling to 40-56° C., 1.5 ml ofcarbon disulfide was added and reacted for 1 hour, and, while keepingthe reaction mixture at 55° C., 3 g of α-bromoisobutylnitrile was addeddropwise and the reaction was continued for 72 hours and then ice waterwas added to the reaction mixture, which was concentrated and extractedtwice with 200 ml of diethylether. After drying the extract withmagnesium sulfate, it was concentrated, 200 ml of methanol was added tothe residue, and after cooling to 0° C., 0.1 ml of 3.6% hydrochloricacid was added and stirring was continued until tetrahydropyranyletherwas deprotected. After the reaction was over, the reaction mixture wasconcentrated and purified by silica gel column chromatography (elutedwith a mixed solvent of ethyl acetate:n-hexane=1:1 (vol/vol)) to obtain4 g of 2-cyanoprop-2-yl-{4-(2-hydroxy-decanoxy)}dithiobenzoate(precursor G) (yield: 55%). 1.3 g (3.3 mmol) of precursor G, 0.35 g (3.5mmol) of succinic anhydride and 0.2 g of triethylamine were dissolved indehydrated toluene, to which 5 mg of dimethylaminopyridine was added andesterification reaction was carried out at room temperature. Sincealmost all precursor G disappeared 6 hours later with TLC, ethyl acetateand water were added to the reaction mixture and extracted. The organicphase was washed with dilute hydrochloric acid and saturated saline,then dried with magnesium sulfate, and concentrated under reducedpressure to obtain 1.68 g of anionic RAFT-3 (yield: 100%).

¹H-NMR (CDCl₃): 1.3-1.5 (ppm): (m, 16H), 1.9 (ppm): (s, 6H), 2.7 (ppm):(m, 4H), 4.0 (ppm): (t, 2H), 4.1 (ppm): (t, 2H), 6.8 (ppm): (d, 2H), 7.9(ppm): (d, 2H)

The HLB value of R¹ of this anionic RAFT-3 was about 5.34(83.111/311.446), and the HLB value of the anionic RAFT-3 as a whole wasabout 3.12.

Working Example 16 Synthesis of RAFT-1 Phosphate

2.06 g (13.4 mmol) of phosphorous oxychloride was introduced to a 30 mlround bottomed flask containing 2.5 g of THF, and cooled to −5° C. witha cryogen. 2.3 g (8.2 mmol) of2-cyanopropyl-2-yl-{4-(2-hydroxy-ethoxy)}dithiobenzoate (precursor E)and 1.2 g (11.9 mmol) of triethylamine were dissolved in 10 g of THF,and added dropwise to the cooled solution of phosphorous oxychloride inTHF. After the dropwise addition was over, stirring was continued for2.5 hours under ice cooling, and then 3 g of dehydrated methanol wasadded and allowed to stand overnight at room temperature. Thetriethylamine chloride that deposited in the reaction mixture wasfiltered off, and the reaction mixture was frozen-concentrated. 1.7 g ofRAFT-1 phosphate was obtained (yield: 60%).

¹H-NMR (D₂O): δ (ppm): (s, xH)

The HLB value of R¹ of this RAFT-1 phosphate was about 14.8(125.04/169.09), and the HLB value of the RAFT-1 phosphate as a wholewas about 6.41.

Synthetic Example 3 Synthesis of RAFT-3

According to Mitsukami et al.'s method in Macromolecule, 2001, vol. 34,pp. 2248, di(dithibenzyl)disulfide was synthesized. Then, into a 100 mlround bottomed flask containing 30 ml of ethyl acetate, 3 g ofdi(dithibenzyl)disulfide and 3 g (11 mmol) of azobis(cyanovaleric acid)were introduced and purged with nitrogen, and then heated to reflux at90° C. in an oil bath for 12 hours. After the reaction was over, it wasconcentrated under reduced pressure, purified by column chromatographyusing 200 g of silica gel to obtain 2.6 g of RAFT-3 (yield: 42.3%).

¹H-NMR (CDCl₃): 1.95 (ppm): (s, 3H), 2.40-2.80 (ppm): (m, 4H), 7.40(ppm): (dd, 2H), 7.58 (ppm): (t, 1H), 7.89 (ppm): (d, 2H)

Since corresponding to R¹ of this RAFT-3 in Chemical formula (1) ishydrogen atom (H—), and the HLB value becomes 0, it does not correspondto the compound of the present invention. The HLB value of the RAFT-3 asa whole is about 5.02.

Working Example 17 Emulsion Polymerization of Isobutyl Methacrylate(IBMA) Using Anionic RAFT-1

6.25 parts of an anionic emulsifying agent (manufactured by Kao, PelexO-TP), 1 part of sodium bicarbonate and 1000 parts of distilled waterwere introduced, and dissolved while purging with nitrogen. Separately asolution in which 1.7 part of anionic RAFT-1 obtained in Working ExampleX was dissolved in 125 parts of IBMA and 2.5 parts of hexadecane wasadded dropwise to an aqueous solution of an anionic emulsifying agent,and, after emulsifying with a homogenizer for 10 minutes, transferred toa baffled separable flask equipped with a condenser and a stirring unitand purged with nitrogen for 30 minutes. After raising the temperatureof the flask to 60° C., 2.5 parts of potassium persulfate was added inone motion, and then samples were collected at the desired times whilestirring.

In the present Working Example, the ratio of the concentration of IBMAand anionic RAFT-1, i.e., [IBMA]/[anionic RAFT-1], is 200, and atheoretical Mn when 100% of IBMA was polymerized is about 28,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 1.

TABLE 1 Time (min) conv(%) Mn Mw Mw/Mn 100 11 12800 18000 1.41 145 2116100 23000 1.43 190 38 20100 29100 1.45 240 67 41400 79900 1.93 290 6944900 86300 1.92

Working Example 18 Emulsion Polymerization of MMA Using Anionic RAFT-2

In a manner similar to Working Example 17 except that 1.0 part ofanionic RAFT-2 in stead of 6.25 parts of anionic RAFT-1 was used, MMAwas emulsion polymerized.

[MMA]/[anionic RAFT-2] of the present Working Example is 510, and atheoretical Mn when 100% of MMA was polymerized is about 51,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 2.

TABLE 2 Time (min) conv(%) Mn Mw Mw/Mn 35 4.4 9000 14700 1.63 65 3652400 67600 1.29 95 81.3 85900 113400 1.32

Working Example 19 Emulsion Polymerization of MMA Using Anionic RAFT-3

In a manner similar to Working Example 17, except that 1.0 part ofanionic RAFT-3 in stead of 6.25 parts of anionic RAFT-1 was used, MMAwas emulsion polymerized.

[MMA]/[anionic RAFT-3] of the present Working Example is 610, and atheoretical Mn when 100% of MMA was polymerized is about 61,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 3.

TABLE 3 Time (min) conv(%) Mn Mw Mw/Mn 0 10.9 9600 16000 1.67 65 19.237500 42400 1.13 80 80.2 111000 138200 1.25

Working Example 20 Emulsion Polymerization of Styrene (St) UsingPEG-RAFT-2

12.5 parts of PEG-RAFT-2 was introduced into 1790 parts of distilledwater, and dissolved while purging with nitrogen. Separately 10 parts ofhexadecane was dissolved in 200 parts of styrene, and the solution wasadded dropwise to an aqueous solution of PEG-RAFT-2, and, afteremulsifying with a homogenizer for 10 minutes, transferred to a baffledseparable flask equipped with a condenser and a stirring unit and purgedwith nitrogen for 30 minutes. After raising the temperature of the flaskto 75° C., 5 parts of potassium persulfate was added in one motion, andthen samples were collected at the desired times while stirring.

In the present Working Example, the ratio of the molar concentration ofSt and PEG-RAFT-2, i.e., [St]/[PEG-RAFT-2] is about 400, and atheoretical Mn when 100% of IBMA is polymerized is about 42,000.

The solid of the samples collected at the desired sampling times wasmeasured, the polymerization conversion ratio was determined, and Mn, Mwand Mw/Mn of the solid were determined by GPC. The results are shown inTable 4.

TABLE 4 Time (min) conv(%) Mn Mw Mw/Mn 105 7 32500 48300 1.48 165 36.539400 56300 1.43 210 52 42700 61000 1.43 260 86.5 62000 120500 1.94

FIGS. 1 to 3 illustrate plots of relationship between the polymerizationtime and the polymerization conversion ratio, relationship between thepolymerization conversion ratio and Mn, and relationship between thepolymerization conversion ratio and Mw/Mn obtained in Working Example 5,Comparative Example 1 and Comparative Example 3.

As can be seen from FIG. 1, the results of Working Example 5 that usedPEG-RAFT-1 show that polymerization is almost complete at 60 minutes ofpolymerization time, and as can be seen from FIG. 2, Mn also increasestogether with the increase in the polymerization conversion ratio and isrelatively consistent with the theoretical line. Also as can be seenfrom FIG. 3, Mw/Mn has been kept low irrespective of the increase in thepolymerization conversion ratio, indicating that polymerization is beingcontrolled.

On the other hand, the results of Comparative Example 1 that used RAFT-1having no PEG chains demonstrate, as can be seen from FIG. 2, that whileMn increases together with the increase in the polymerization conversionratio, it exhibits a behavior slightly off the theoretical line. Also,as can be seen from FIG. 3, Mw/Mn is not so narrow as the results inWorking Example 5, indicating that the polymerization controllingability is poorer than Working Example 5.

The results in Comparative Example 3 show, as can also be seen fromTable 3, that molecular weight is kept low, a chart obtained by GPCshows multi peaks, and Mw/Mn gives a very broad result, indicating thatpolymerization is not controlled.

FIGS. 4 to 6 illustrate plots of relationship between the polymerizationtime and the polymerization conversion ratio, relationship between thepolymerization conversion ratio and Mn, and relationship between thepolymerization conversion ratio and Mw/Mn obtained in Working Example 6,Comparative Example 2 and Comparative Example 4.

As can be seen from FIG. 4, the results of Working Example 6 that usedPEG-RAFT-1 show that polymerization gradually proceeds until 120 minutesof polymerization time, and as can be seen from FIG. 5, Mn alsoincreases together with the increase in the polymerization conversionratio. Also as can be seen from FIG. 3, Mw/Mn is kept low irrespectiveof the increase in the polymerization conversion ratio, indicating thatpolymerization is being controlled.

On the other hand, the results of Comparative Example 2 that used RAFT-1having no PEG chains demonstrate, as can be seen from FIG. 6, that Mw/Mnis not so narrow as the results in Working Example 6, indicating thatthe polymerization controlling ability is poorer than Working Example 6.

The results in Comparative Example 4 show, as can also be seen from FIG.7, similarly to the results of Comparative Example 3, that molecularweight is kept low, a chart obtained by GPC shows multi peaks, and Mw/Mngives a very broad result, indicating that polymerization is notcontrolled.

FIGS. 7 to 9 illustrate plots of relationship between the polymerizationtime and the polymerization conversion ratio, relationship between thepolymerization conversion ratio and Mn, and relationship between thepolymerization conversion ratio and Mw/Mn obtained in Working Examples 7to 9.

As can be seen from FIG. 7, the results of Working Example 7 that usedPEG-RAFT-1 in which PEG has a molecular weight of 750 show thatpolymerization is almost complete at 90 minutes of polymerization time,and Working Examples 8 and 9 that used PEG-RAFT-2 and 3 with a molecularweight of PEG being 2000 and 5000, respectively, show that thepolymerization speed is slowed. Also as can be seen from FIG. 8, theresults of Working Example 7 indicate that Mn also increases togetherwith the increase in the polymerization conversion ratio and isrelatively consistent with the theoretical line.

In Working Examples 8 and 9, molecular weight at the initial stage ofpolymerization is far off the theoretical line, but at the late stage ofpolymerization it exhibits a behavior of nearing the theoretical line.As can be seen from FIG. 9, the results of Working Examples 7 to 9demonstrate that Mw/Mn is kept low irrespective of the increase in thepolymerization conversion ratio, indicating that polymerization is beingcontrolled.

FIGS. 10 to 12 illustrate plots of relationship between thepolymerization time and the polymerization conversion ratio,relationship between the polymerization conversion ratio and Mn, andrelationship between the polymerization conversion ratio and Mw/Mnobtained in Working Example 10 and Comparative Example 5. In WorkingExample 10 and Comparative Example 5, the RAFT agent previouslydissolved in MMA was added to the polymerization system prior topolymerization, and an effect of the order of adding the RAFT agent onpolymerization behavior was examined.

As can be seen from FIG. 11, the results of Working Example 10 andComparative Example 5 that used PEG-RAFT-1 and RAFT-1 show that thoughMn is off the theoretical line in both cases, it also increases togetherwith the increase in the polymerization conversion ratio. Also as can beseen from FIG. 12, the results of Working Example 10 show that Mw/Mn iskept low irrespective of the increase in the polymerization conversionratio, indicating that polymerization is being controlled, but inComparative Example 5 the polymerization controlling ability isdecreased with the increase in the polymerization conversion ratio.

TABLE 5 Working Example 5 Working Example 6 Polymeri- Polymeri-Polymeri- zation zation zation conversion conversion time (min) ratio(%) Mn Mw/Mn ratio (%) Mn Mw/Mn 0 0.0 0.0 15 10.8 52700 1.59 10.8 151001.45 30 21.5 95400 1.65 13.4 14600 1.66 45 87.4 234000 1.19 17.5 190001.69 60 89.6 229000 1.22 28.2 32000 1.41 90 91.4 229000 1.23 61.8 566001.33 120 94.4 236000 1.26 84.7 70700 1.42

TABLE 6 Working Example 7 Working Example 8 Working Example 9Polymeriza- Polymerization Polymeriza- Polymerization Polymeriza-Polymerization tion time conversion tion time conversion tion timeconversion (min) ratio (%) Mn Mw/Mn (min) ratio (%) Mn Mw/Mn (min) ratio(%) Mn Mw/Mn 0 0.0 0 0.0 0 0.0 15 2.0 20 2.9 146000 1.38 30 4.6 1790001.29 30 5.2 40700 1.34 40 9.9 158000 1.36 50 12.0 208000 1.31 60 29.1107000 1.25 60 18.3 177000 1.33 70 22.9 254000 1.28 90 93.7 282000 1.0980 29.9 203000 1.30 90 36.1 287000 1.26 120 94.9 285000 1.09 100 48.0248000 1.26 110 66.4 344000 1.24 120 76.6 260000 1.33 130 78.9 3200001.30 150 82.4 265000 1.30 160 83.3 325000 1.29

TABLE 7 Comparative Example 1 Comparative Example 2 Comparative Example3 Comparative Example 4 Polymeriza- Polymerization PolymerizationPolymerization Polymerization tion time conversion Mw/ conversion Mw/conversion Mw/ conversion Mw/ (min) ratio (%) Mn Mn ratio (%) Mn Mnratio (%) Mn Mn ratio (%) Mn Mn 0 0.0 0.0 0.0 0.0 15 0.3 20500 1.59 4.618500 5.99 72.9 3300 60.9 67.4 3070 69.6 30 16.1 47500 2.42 6.5 91003.83 92.1 4200 53.0 88.1 3020 73.9 45 31.5 62000 1.76 10.7 10400 1.7489.3 3090 58.9 87.7 2310 95.5 60 83.2 164000 1.60 15.5 10300 1.82 90.53830 57.3 87.4 3710 58.2 90 88.1 165000 1.71 31.1 15900 1.67 89.5 467051.9 88.0 2730 83.4 120 90.7 162000 1.73 82.0 46000 1.94 90.0 3860 45.687.3 2620 86.8

TABLE 8 Working Example 10 Comparative Example 5 PolymerizationPolymerization Polymerization conversion Polymerization conversion time(min) ratio (%) Mn Mw/Mn time (min) ratio (%) Mn Mw/Mn 0 0.0 0 0.0 605.7 30 4.3 90 6.7 60 7.6 120 8.5 12300 1.24 90 9.3 10100 1.30 180 11.313600 1.23 120 12.4 10300 1.34 240 20.2 16400 1.21 180 17.3 12500 1.34270 23.6 17600 1.22 240 25.5 18000 1.33 300 28.1 19100 1.25 300 71.445400 2.06 345 32.7 22600 1.26 360 96.9 54100 2.13 390 42.3 28800 1.31450 82.6 47900 1.51 485 85.6 49400 1.54

INDUSTRIAL APPLICABILITY

Emulsion polymerization using the compound of the present inventionenables to control radical polymerization up to a high conversion ratio,and is an industrially excellent polymerization method. Also, from thepolymer obtained, the RAFT agent can be easily removed, a colorlesspolymer can be obtained, and the polymer obtained can be used in opticalapplications.

1. A compound represented by the following general formula (1):

wherein, R¹ represents an organic group having a hydrophile-lipophilebalance (HLB) determined by Griffin's method of 3 or more, Z representsa nitrogen atom, an oxygen atom, a sulfur atom, a methylene group, or anunsubstituted aromatic hydrocarbon group, R¹ represents, when Z is otherthan a sulfur atom, a monovalent organic group having one or morecarbons, and said monovalent organic group may comprise at least one ofa nitrogen atom, an oxygen atom, a sulfur atom, a halogen atom, asilicon atom and a phosphorous atom and may represent a high molecularweight substance, R¹ represents, when Z is a sulfur atom, a monovalentaliphatic hydrocarbon group or aromatic hydrocarbon group having one ormore carbons that bind(s) to the sulfur atom at a primary carbon, andsaid monovalent hydrocarbon group may comprise at least one of anitrogen atom, an oxygen atom, a sulfur atom, a halogen atom, a siliconatom and a phosphorous atom, and may represent a high molecular weightsubstance; when a plurality of R¹ are present, they may be the same ordifferent; and p is represented by an integer of 1 or more, and R² is ap-valent organic group having one or more carbons, and said p-valentorganic group may comprise at least one of a nitrogen atom, an oxygenatom, a sulfur atom, a halogen atom, a silicon atom, a phosphorous atomand a metal atom, and may represent a high molecular weight substance.2. A method for radical-polymerizing a vinyl monomer using the compoundaccording to claim
 1. 3. A radical polymerization method according toclaim 2 that employs emulsion polymerization.
 4. A method for radicalpolymerizing a vinyl monomer, which method comprises preparing anaqueous solution having the compound according to claim 1 and anemulsifying agent mixed therein using emulsion polymerization prior toadding the vinyl monomer.
 5. A radical polymerization method accordingto claims 2 to 4, wherein after a first vinyl monomer or a mixturethereof was polymerized, a second vinyl monomer or a mixture thereof isnewly added to produce a diblock copolymer.
 6. The radicalpolymerization method according to claims 2 to 4, wherein after a firstvinyl monomer or a mixture thereof was polymerized, a second vinylmonomer or a mixture thereof is added and polymerized, and then a vinylmonomer or a mixture thereof is added and polymerized in multi stages toproduce a multiblock copolymer.
 7. A polymer obtained by thepolymerization method according to claims 2 to
 6. 8. A method ofremoving the unit of the following general formula (2) from the polymeraccording to claim 7 using an azo compound or a peroxide:

wherein, R¹ represents an organic group having a hydrophile-lipophilebalance (HLB) determined by Griffin's method of 3 or more, Z representsa nitrogen atom, an oxygen atom, a sulfur atom, a methylene group, or anunsubstituted aromatic hydrocarbon group, R¹ represents, when Z is otherthan a sulfur atom, a monovalent organic group having one or morecarbons, and said monovalent organic group may comprise at least one ofa nitrogen atom, an oxygen atom, a sulfur atom, a halogen atom, asilicon atom and a phosphorous atom and may represent a high molecularweight substance, and R¹ represents, when Z is a sulfur atom, amonovalent aliphatic hydrocarbon group or aromatic hydrocarbon grouphaving one or more carbons that bind(s) to the sulfur atom at a primarycarbon, and said monovalent hydrocarbon group may comprise at least oneof a nitrogen atom, an oxygen atom, a sulfur atom, a halogen atom, asilicon atom and a phosphorous atom, or may represent a high molecularweight substance.
 9. A method of removing the unit of the followinggeneral formula (3) from the polymer according to claim 7 using an aminecompound:

wherein, R¹ represents an organic group having a hydrophile-lipophilebalance (HLB) determined by Griffin's method of 3 or more, Z representsa nitrogen atom, an oxygen atom, a sulfur atom, a methylene group, or anunsubstituted aromatic hydrocarbon group, R¹ represents, when Z is otherthan a sulfur atom, a monovalent organic group having one or morecarbons, and said monovalent organic group may comprise at least one ofa nitrogen atom, an oxygen atom, a sulfur atom, a halogen atom, asilicon atom and a phosphorous atom and may represent a high molecularweight substance, and R¹ represents, when Z is a sulfur atom, amonovalent aliphatic hydrocarbon group or aromatic hydrocarbon grouphaving one or more carbons that bind(s) to the sulfur atom at a primarycarbon, and said monovalent hydrocarbon group may comprise at least oneof a nitrogen atom, an oxygen atom, a sulfur atom, a halogen atom, asilicon atom and a phosphorous atom, or may represent a high molecularweight substance.
 10. A polymer obtained by the method according toclaim 8 or
 9. 11. A thermoplastic resin composition comprising thepolymer according to claim
 10. 12. A formed body obtained by forming thethermoplastic resin composition according to claim 11.